According to the International Energy Agency and the World Bank, over 1.2 billion people, or 20% of the world's population, do not have access to electricity. This means that 1 in 5 people do not have the luxury of walking into a room and flipping on a light switch.

Many people who do not have access to electricity burn kerosene to light their homes and buildings. The problem with kerosene is that it's dirty, expensive, and toxic. When burned for lighting, 7-8% of kerosene is converted to black carbon, according to the National Institute of Health Sciences. This not only pollutes the atmosphere with greenhouse gases, but also fills people's lungs with dangerous smoke and soot. These toxins cause lung and respiratory problems, and kerosene accidents cause tens of thousands of serious injuries and deaths each year. In Kenya, more women die of fume-related illnesses than of malaria and tuberculosis, according to UNDP.

Kerosene is also very costly, making it very difficult for already impoverished families to afford lighting. According to Dr. Evan Mills, the founder of the Lumina Project, and his colleagues at the Berkeley Laboratory at the University of California, kerosene-powered light costs hundreds of times more per lumen than electric lighting. As Dr. Mills said of people who use kerosene-powered lighting, "in real terms, they contribute a fifth of all the money spent on lighting globally, but get less than 1% of the total lumens".

That's where solar lighting comes in. Solar powered lighting requires no connection to the grid, which makes steady, clean lighting possible for the 5th of the world without electricity. Once installed, the lighting is free of emissions and utility costs, making it ideal for low-income, third world populations.

Despite this, there remain challenges to solar powered lighting: installation and upfront cost. Solar competes with the highly subsidized kerosene for pricing. Plus, many solar photovoltaic systems require skilled labor for the installation. These 5 organizations or movements are saving the world by giving people the tools to install affordable solar powered lighting, either through simple design, low-cost materials, or courses in solar installation.

1. Liter of Light

In 2002, Alfred Moser, a mechanic in Uberaba, Brazil, invented a plastic bottle lamp powered by the sun. He was inspired by the frequent blackouts in his town, which would leave homes and smaller buildings in the dark. The lamp is incredibly simple: it's built using a plastic bottle filled with water and bleach (to prevent algae). When installed in a hole in the roof, it refracts the sunlight to illuminate the inside. The bottle can be sealed into the roof with polyester resin, making it leak-proof.

Moser began installing the lights in his neighbors' homes and in supermarkets for a small income. Later, in 2011, MyShelter Foundation began installing similar plastic bottle-based lamps in the Philippines, this time with a design from students at the Massachusetts Institute of Technology. The organization's project, called Liter of Light, installed over 200,000 lights during its first year alone.

MyShelter Foundation trains people in developing countries to assemble and install the lights, so they can make a small income by giving off-the-grid communities much-needed light. The technology is spreading rapidly, with about 15 countries installing the plastic bottle lights. MyShelter expects that over 1 million people will have benefitted from the lights by next year.

The LuminAID was designed by Anna Stork and Andrea Sreshta, two architecture and design grad school students who were on a school trip to Japan during the earthquake in March 2011. Inspired by the need for off-the-grid lighting after natural disasters, the two women created the LuminAID, an inflatable, waterproof lamp that will produce 16 hours of light after charging in the sun for 6-7 hours. The light is unique because it packs flat and expands to create a lantern-like structure, making it easy and cheap to produce, pack and ship. Anyone who purchases a LuminAID will fund the donation of another LuminAID to someone in need of affordable lighting. So far, the project has partnered with several organizations to distribute thousands of LuminAIDs to people in 12 countries.

Credit: Eric Hersman3. The Portable Light Project

The Portable Light Project 's design leverages the constant mobility of the people in the developing world. Kennedy & Violich Architecture developed Portable Light's solar textile, which allows people to integrate the fabric into their clothes, bags and blankets.

A Portable Light kit includes a textile reflector, flexible photovoltaic material, a battery case with a USB port and an LED light. The photovoltaic material fully charges in 6 hours of sunlight, storing over 20 hours worth of LED light. The solar textile also charges USB-enabled tools, such as cell phones and medical devices. Since the battery is carried on the person, it can be used anywhere, making task lighting and electric charging readily accessible on-the-go.

So far, the Portable Light has been piloted in Mexico, Haiti, Brazil, Kenya, Venezuela, South Africa, and Nicaragua.

4. Barefoot College

Barefoot College is an India-based NGO that trains middle-aged women in India and other developing countries to provide much needed services and solutions to their communities. The school has a Solar Electrification division that specifically trains grandmothers to install solar lighting systems in their villages.

Each year, Barefoot College holds two 6-month training classes, each with an enrollment of 100 women from India and 80 from other countries. Barefoot College helps to set up a solar committee in each woman's village, which will pay her to install solar lighting systems for the next 5 years. Therefore, the grandmothers return to their villages with a valuable, profitable skills and newfound confidence in their abilities to understand and execute complex ideas.

Since 2008, the graduates of the Solar Electrification program have installed solar lighting systems in over 40,000 households, giving light to more than 450,000 people in 1,015 villages.Credit: Dan Lundmark5. Earthquake Relief in Haiti

Prior to Haiti's earthquake on January 12, 2010, the nation has one of the lowest electricity access rates in the world, with 12.5% of the country in the dark, according to National Geographic. After the earthquake, blackouts and diesel price spikes made it even more difficult for the impoverished and displaced natives to find electricity.

As such, solar powered lighting became an important element of Haiti's disaster relief. Poorly lit or dark emergency tents were boons for sexual violence and assaults. Over 35,000 donated solar lamps, including a donation of 6,500 solar light systems by the Good Energies Foundation, for the tents were vital to security in the camps. Following the earthquake, those systems could be installed on homes and in buildings. In addition, the Solar Electric Light Fund (SELF) installed solar PV to power eight health centers in the region, which helped injured residents to recover.

Following the earthquake's aftermath, the trend in solar lighting has continued. For example, Mirebalais, an hour northeast of Port-au-Prince, is now home to the world's largest solar hospital. Additionally, a non-profit, EarthSpark International, is planning to expand Haiti's first prepay microgrid, powered by a 100-kilowatt solar PV system, by this summer.